The above three assumptions have the following implications. The first assumption characterize the selfish and competitive nature of the travelers' behavior; it is also known as the Wardrop equilibrium principle [1]} and has been the basis of static traffic equilibria models [2]}. The second assumption states that the traffic flow on a road segment is upper bounded–typically due to the number of lanes and the green light time–and the total air traffic flow at a vertiport is upper bounded–typically due to the number of touchdown and lift-off pads. The third assumption is based on the empirical observation that the travel time on a road segment (or the delay at a vertiport) is at its minimum when there is no congestion, and increase with the congestion level. Similar assumptions were first introduced in the Nesterov & de Palma model for ground traffic equilibria [3]}. Here we add two additional assumptions on the capacity and delay at vertiports.
